December is far from over and the approaching cold front could help bring the region close to the chilliest temperatures seen yet this season, according to the National Weather Service, Melbourne.

Expect overnight lows in the lower 50s during the early-morning hours Saturday after a front starts moving in Thursday.

Weekend daytime highs should be around 70 degrees, and could dip into the upper 60s Saturday.

Winter begins Dec. 21, and December typically is the coldest month of the year on the Treasure Coast.

December's highs normally average 74.2 degrees in Vero Beach, 74.6 in Fort Pierce and 75.3 in Stuart. Melbourne's is 73.3

This month has been off to an unusually warm start, with highs around 80. Stuart's daytime high Saturday was 4.7 degrees above normal. Vero Beach's Friday high was 4.2 degrees above the average. Melbourne's highs have been from 5.6 to 6 degrees above normal.

So far this fall, the lowest highs came Oct. 30: 67 in Vero Beach, 68 in Fort Pierce and 74 in Stuart. At the same time, overnight lows briefly were in the upper 40s in Vero Beach and Fort Pierce and 50 in Stuart on the last day of October. Melbourne was slightly cooler.

Cold fronts also increase rain chances. There is a 30 percent chance for rain Thursday and a 50 percent Friday. Rain chances drop to 20 percent under partly cloudy skies for the weekend.